Prognostic value of embryo age and morphokinetic parameters for the probability of a positive outcome in an IVF program

   Introduction. With the expansion of single embryo transfer practices, selecting the most competent embryo is becoming critical for achieving high reproductive outcomes. Morphological assessment, including the Gardner classification, remains a widely used tool; however, its prognostic value remains limited and variable. Time-lapse imaging technology
allows for recording embryo morphokinetic parameters and developing implantation prediction algorithms based on the timing of key developmental stages. Research shows the influence of a number of factors — woman’s age, body weight, smoking, and endometriosis — on morphokinetic parameters. However, the advantages of TLM over traditional culture remain unclear. Nevertheless, the use of time-lapse imaging can improve the accuracy of embryo selection, including the selection of candidates for transfer or PGT-A, which is particularly important in patients of advanced reproductive age.

   Objective. To identify prognostic factors for a positive IVF outcome based on classification tree analysis.

   Materials and methods. Data from 431 IVF cycles were analyzed. A positive outcome was defined as clinical pregnancy, and a negative outcome was defined as its absence. The CHAID method was used to identify significant predictors. The analysis included patient age and morphokinetic parameters of embryo development by day 5 of culture.

   Results. The key discriminatory factor was patient age (≤ 35 years) (p = 0.004). In this group, the success rate was 47.8 %, compared to 31.0 % in patients over 35 years of age. Among women ≤ 35 years of age, the most significant factor was the morphokinetic assessment score (AI score on day 5, p = 0.001): with a score > 9.4, the probability of a successful outcome reached 72.5 %, while with a score ≤ 5.1, it was only 30.3 %. A similar pattern persisted in patients over 35 years of age (p < 0.001), but the success rate with high scores decreased to 46.5 %.

   Conclusion. Patient age and embryo morphokinetic assessment are independent predictors of IVF success. Using a classification tree allows for personalized outcome prognosis and optimized embryo transfer strategies.

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